What is the recommended treatment for a 75-year-old female with coronary artery disease (CAD) and atrial fibrillation (AF) who has undergone stent placement?

Treatment for 75-Year-Old Female with CAD, Stent Placement, and Atrial Fibrillation

For a 75-year-old female with coronary artery disease who has undergone stent placement and has atrial fibrillation, the recommended treatment is initial triple therapy (oral anticoagulant plus dual antiplatelet therapy) for 1-3 months, followed by dual therapy (oral anticoagulant plus clopidogrel) for up to 6-12 months, and then oral anticoagulant monotherapy long-term. 1

Initial Assessment

Before finalizing the treatment plan, two key assessments are necessary:

1. Stroke risk assessment using the CHA₂DS₂-VASc score 1

   • At 75 years old, female with CAD, this patient already has a minimum score of 3 (age ≥75 = 2 points, female = 1 point)
   • This indicates a high stroke risk requiring oral anticoagulation

2. Bleeding risk assessment using the HAS-BLED score 1

   • Evaluate for hypertension, abnormal renal/liver function, stroke history, bleeding history, labile INR, elderly (>65), and drugs/alcohol

Treatment Algorithm

Phase 1: Initial Post-Stent Period

• If bleeding risk is low (HAS-BLED 0-2):

  • Triple therapy for 1-3 months: OAC + aspirin + clopidogrel 1

• If bleeding risk is high (HAS-BLED ≥3):

  • Triple therapy for 1 month only: OAC + aspirin + clopidogrel 1

• If bleeding risk is unusually high:

  • Consider skipping triple therapy and use dual therapy: OAC + clopidogrel 1

Phase 2: Intermediate Period

• If bleeding risk is low:

  • Dual therapy for up to 12 months: OAC + clopidogrel 1

• If bleeding risk is high:

  • Dual therapy for 6 months: OAC + clopidogrel 1

Phase 3: Long-term Management

• All patients: OAC monotherapy indefinitely 1

Medication Specifics

Oral Anticoagulant (OAC)

• Preferred: Non-vitamin K antagonist oral anticoagulant (NOAC) at doses licensed for stroke prevention in AF 1

  • NOACs have lower bleeding risk compared to VKA-based strategies 1
  • Options with evidence in this setting include:
    • Dabigatran 150mg twice daily or 110mg twice daily 1
    • Rivaroxaban 15mg daily 1

• Alternative: Vitamin K antagonist (warfarin) with TTR >65-70% (INR 2.0-3.0) 1

Antiplatelet Therapy

• P2Y₁₂ inhibitor: Clopidogrel 75mg daily is preferred 1

  • Avoid prasugrel or ticagrelor due to increased bleeding risk 1

• Aspirin: Use low-dose (75-100mg daily) with concomitant PPI to minimize GI bleeding 1

Special Considerations

Timing of Triple Therapy

• The highest risk of bleeding occurs within the first 30 days of triple therapy initiation 1
• Bleeding risk with triple therapy is approximately twice as high as the risk of acute coronary events 1

Stent Type Considerations

• Drug-eluting stents may require longer duration of dual antiplatelet coverage
• Bare metal stents may allow for shorter duration of antiplatelet therapy

Monitoring Requirements

• More frequent follow-up is necessary for patients with high bleeding risk (HAS-BLED ≥3) 1
• Regular assessment of renal function for NOAC dosing
• INR monitoring if using warfarin

Common Pitfalls to Avoid

1. Prolonged triple therapy - Extending triple therapy beyond necessary periods significantly increases bleeding risk without providing additional ischemic protection 1, 2

2. Suboptimal anticoagulation - Inadequate stroke prevention in AF patients with CAD leads to increased morbidity and mortality 3

3. Using prasugrel or ticagrelor in triple therapy - These more potent P2Y₁₂ inhibitors increase bleeding risk substantially when combined with anticoagulation 1

4. Omitting PPI therapy - Gastric protection is essential when combining antiplatelets with anticoagulants 1

5. Failure to reassess therapy - Antithrombotic regimens should be reevaluated at regular intervals to ensure appropriate duration of combination therapy 1